How to ensure the quality of pneumatic hoist accessories?

Pneumatic hoist is the core equipment of industrial lifting. The quality of its accessories (hook, chain, cylinder, sealing ring, etc.) is directly related to operational safety and lifespan. Especially in high-frequency lifting scenarios such as machinery manufacturing and warehousing and logistics, defects in accessories can easily cause accidents such as falling and air leakage. It is necessary to build a complete quality system covering "production-testing-after-sales" through refined control of raw material control, process specifications, and full-process testing to ensure compliance with industrial safety standards.

Raw material control is the foundation. Load-bearing parts (hooks, chains) are made of high-strength alloy steel (20Mn2, 35CrMo), with tensile strength ≥800MPa and yield strength ≥650MPa. They must pass a static load test of 1.5 times the rated load (no change for 10 minutes shape); the pneumatic transmission parts (cylinder, valve body) are made of wear-resistant cast iron (HT300) or seamless steel pipe (20# steel), and the inner wall roughness is ≤ Ra0.8um to avoid gas leakage affecting the lifting efficiency; the seals are made of oil-resistant nitrile rubber (hardness 50-70 ShoreA), there is no leakage under the working pressure of 0.6-1.2MPa for 30 minutes. When purchasing, you need to verify the material certificate issued by the steel factory. Each batch is randomly sampled for spectral analysis (to verify the purity of the ingredients) and tensile testing (to detect mechanical properties) to prevent unqualified materials from flowing into the production line. Standardization of production processes is the core. The chain needs to be forged, quenched and tempered, heat treated (hardness controlled at HRC28-32), and ground. The matching gap between the chain links is strictly controlled at 0.1-0.3mm to prevent jamming or increased wear during operation; the hook is formed in one go using the die forging process to reduce internal stress concentration. After forming, it is sprayed Shot treatment (pellet diameter 0.8-1.2mm) improves surface fatigue strength; the cylinder is processed with a CNC lathe (precision grade IT7) to process the inner and outer circles, and the honing process (honing head speed 800-1200r/min) ensures the smoothness of the inner wall. Finally, anodizing treatment is performed to enhance corrosion resistance. Key welding processes (such as chain connectors) use carbon dioxide gas shielded welding, and the welding current is controlled at 180-220A. Penetration testing is required after welding to ensure that there are no defects such as cracks and pores, and the welding strength is not less than 90% of the strength of the base metal.